scholarly journals Anti-CD20 Treatment Effectively Attenuates Cortical Pathology in a Rat Model of Widespread Cortical Demyelination

2021 ◽  
Author(s):  
Michaela T Haindl ◽  
Muammer Üçal ◽  
Benjamin Klaus ◽  
Lennart Tögl ◽  
Jana Dohrmann ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Rat Model ◽  
Apoptotic Cell ◽  
Cell Loss ◽  
Relapsing Remitting ◽  
Cortical Pathology ◽  
Cd20 Antibody ◽  
Set Up ◽  
Anti Cd20

Abstract BackgroundCortical demyelination represents a prominent feature of the multiple sclerosis (MS) brain, especially in (late) progressive stages. We recently developed a new rat model that reassembles critical features of cortical pathology characteristic to progressive types of MS. In persons affected by MS, B-cell depleting anti-CD20 therapy proved successful in the relapsing remitting as well as the early progressive course of MS, with respect to reducing the relapse rate and number of newly formed lesions. However, if the development of cortical pathology can be prevented or at least slowed down is still not clear. The main goal of this study was thus to increase our understanding for the mode of action (MOD) of B-cells and B-cell directed therapy on cortical lesions in our rat model. MethodsFor this purpose, we set up two separate experiments, with two different induction modes of B-cell depletion. Brain tissues were analyzed thoroughly using histology. ResultsWe observed a marked reduction of cortical demyelination, microglial activation, astrocytic reaction and apoptotic cell loss in anti-CD20 antibody treated groups. At the same time, we noted increased neuronal preservation compared to control groups, indicating a favorable impact of anti-CD20 therapy. ConclusionThese findings might pave the way for further research on the MOD of B-cells and therefore help to improve therapeutic options for progressive MS.

scholarly journals Anti-CD20 treatment effectively attenuates cortical pathology in a rat model of widespread cortical demyelination

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Michaela T. Haindl ◽  
Muammer Üçal ◽  
Benjamin Klaus ◽  
Lennart Tögl ◽  
Jana Dohrmann ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Rat Model ◽  
Mode Of Action ◽  
Apoptotic Cell ◽  
Cell Loss ◽  
Relapsing Remitting ◽  
Cortical Pathology ◽  
Set Up ◽  
Anti Cd20

Abstract Background Cortical demyelination represents a prominent feature of the multiple sclerosis (MS) brain, especially in (late) progressive stages. We recently developed a new rat model that reassembles critical features of cortical pathology characteristic to progressive types of MS. In persons affected by MS, B-cell depleting anti-CD20 therapy proved successful in the relapsing remitting as well as the early progressive course of MS, with respect to reducing the relapse rate and number of newly formed lesions. However, if the development of cortical pathology can be prevented or at least slowed down is still not clear. The main goal of this study was thus to increase our understanding for the mode of action of B-cells and B-cell directed therapy on cortical lesions in our rat model. Methods For this purpose, we set up two separate experiments, with two different induction modes of B-cell depletion. Brain tissues were analyzed thoroughly using histology. Results We observed a marked reduction of cortical demyelination, microglial activation, astrocytic reaction, and apoptotic cell loss in anti-CD20 antibody treated groups. At the same time, we noted increased neuronal preservation compared to control groups, indicating a favorable impact of anti-CD20 therapy. Conclusion These findings might pave the way for further research on the mode of action of B-cells and therefore help to improve therapeutic options for progressive MS.

scholarly journals Phase I clinical trial using escalating single-dose infusion of chimeric anti-CD20 monoclonal antibody (IDEC-C2B8) in patients with recurrent B-cell lymphoma

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2457-2466 ◽  
Author(s):  
DG Maloney ◽  
TM Liles ◽  
DK Czerwinski ◽  
C Waldichuk ◽  
J Rosenberg ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Single Dose ◽  
B Cells ◽  
Phase I ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Chimeric Antibody ◽  
Cd20 Antibody ◽  
Anti Cd20

The B-cell antigen CD20 is expressed on normal B cells and by nearly all B-cell lymphomas. This nonmodulating antigen provides an excellent target for antibody-directed therapies. A chimeric anti-CD20 antibody (IDEC-C2B8), consisting of human IgG1-kappa constant regions and variable regions from the murine monoclonal anti-CD20 antibody IDEC- 2B8, has been produced for clinical trials. It lyses CD20+ cells in vitro via complement and antibody-dependent cell-mediated lysis. Preclinical studies have shown that the chimeric antibody selectively depletes B cells in blood and lymph nodes in macaque monkeys. In this phase I clinical trial, 15 patients (3 per dose level) with relapsed low-grade B-cell lymphoma were treated with a single dose (10, 50, 100, 250, or 500 mg/m2) of antibody administered intravenously. Treatment- related symptoms correlated with the number of circulating CD20 cells and grade II events consisted of fever (5 patients); nausea (2), rigor (2), orthostatic hypotension (2), bronchospasm (1), and thrombocytopenia (1). No significant toxicities were observed during the 3 months of follow-up. Serum C3, IgG, and IgM levels, neutrophils, and T cells were largely unchanged. At the three higher dose levels, pharmacokinetics of the free antibody showed a serum half-life of 4.4 days (range, 1.6 to 10.5). Levels greater than 10 micrograms/mL persisted in 6 of 9 patients for more than 14 days. No quantifiable immune responses to the infused antibody have been detected. CD20+ B cells were rapidly and specifically depleted in the peripheral blood at 24 to 72 hours and remained depleted for at least 2 to 3 months in most patients. Two-week postinfusion tumor biopsies showed the chimeric antibody bound to tumor cells and a decrease in the percentage of B cells. Tumor regressions occurred in 6 of 15 patients (2 partial and 4 minor responses). The results of this single-dose trial have been used to design a multiple-dose phase I/II study.

scholarly journals Activation of natural killer cells by rituximab in granulomatosis with polyangiitis

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Doris Urlaub ◽  
Shuyang Zhao ◽  
Norbert Blank ◽  
Raoul Bergner ◽  
Maren Claus ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Mechanism Of Action ◽  
Granulomatosis With Polyangiitis ◽  
Color Flow ◽  
Cd20 Antibody ◽  
Anti Cd20

Abstract Objective In the last few years, anti-CD20 antibody rituximab profoundly changed the therapeutic landscape of granulomatosis with polyangiitis (GPA). Here, we investigated whether natural killer (NK) cells may play a role in rituximab’s mechanism of action in GPA. Methods B cell depletion, NK cell degranulation, and the expression of CD69 and CD16 on NK cells were measured in a series of in vitro experiments using peripheral blood mononuclear cells (PBMCs). In vivo activation of NK cells was investigated in patients receiving rituximab infusions. Cells were analyzed by seven-color flow cytometry. Results NK cells from GPA patients were activated by immobilized rituximab. Also soluble rituximab activated NK cells, provided that B cells were present. NK cells degranulated and expressed the activation marker CD69 while CD16 expression was decreased. This activation of NK cells by soluble rituximab was accompanied by a reduction of B cells. The next-generation anti-CD20 antibody obinutuzumab showed stronger effects compared to rituximab on both the reduction of B cells and the activation of NK cells. Finally, we found that rituximab led to the activation of NK cells in vivo, provided that B cells were not depleted due to prior rituximab infusions. Conclusion B cell-bound rituximab activates NK cells in GPA. While NK cells therefore participate in rituximab’s mechanism of action in humans, their potential may be more efficiently exploited, e.g., by Fc engineering of therapeutic antibodies.

scholarly journals Phase I clinical trial using escalating single-dose infusion of chimeric anti-CD20 monoclonal antibody (IDEC-C2B8) in patients with recurrent B-cell lymphoma

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2457-2466 ◽  
Author(s):  
DG Maloney ◽  
TM Liles ◽  
DK Czerwinski ◽  
C Waldichuk ◽  
J Rosenberg ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Single Dose ◽  
B Cells ◽  
Phase I ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Chimeric Antibody ◽  
Cd20 Antibody ◽  
Anti Cd20

Abstract The B-cell antigen CD20 is expressed on normal B cells and by nearly all B-cell lymphomas. This nonmodulating antigen provides an excellent target for antibody-directed therapies. A chimeric anti-CD20 antibody (IDEC-C2B8), consisting of human IgG1-kappa constant regions and variable regions from the murine monoclonal anti-CD20 antibody IDEC- 2B8, has been produced for clinical trials. It lyses CD20+ cells in vitro via complement and antibody-dependent cell-mediated lysis. Preclinical studies have shown that the chimeric antibody selectively depletes B cells in blood and lymph nodes in macaque monkeys. In this phase I clinical trial, 15 patients (3 per dose level) with relapsed low-grade B-cell lymphoma were treated with a single dose (10, 50, 100, 250, or 500 mg/m2) of antibody administered intravenously. Treatment- related symptoms correlated with the number of circulating CD20 cells and grade II events consisted of fever (5 patients); nausea (2), rigor (2), orthostatic hypotension (2), bronchospasm (1), and thrombocytopenia (1). No significant toxicities were observed during the 3 months of follow-up. Serum C3, IgG, and IgM levels, neutrophils, and T cells were largely unchanged. At the three higher dose levels, pharmacokinetics of the free antibody showed a serum half-life of 4.4 days (range, 1.6 to 10.5). Levels greater than 10 micrograms/mL persisted in 6 of 9 patients for more than 14 days. No quantifiable immune responses to the infused antibody have been detected. CD20+ B cells were rapidly and specifically depleted in the peripheral blood at 24 to 72 hours and remained depleted for at least 2 to 3 months in most patients. Two-week postinfusion tumor biopsies showed the chimeric antibody bound to tumor cells and a decrease in the percentage of B cells. Tumor regressions occurred in 6 of 15 patients (2 partial and 4 minor responses). The results of this single-dose trial have been used to design a multiple-dose phase I/II study.

scholarly journals The Innate Mononuclear Phagocyte Network Depletes B Lymphocytes through Fc Receptor–dependent Mechanisms during Anti-CD20 Antibody Immunotherapy

2004 ◽  
Vol 199 (12) ◽  
pp. 1659-1669 ◽  
Author(s):  
Junji Uchida ◽  
Yasuhito Hamaguchi ◽  
Julie A. Oliver ◽  
Jeffrey V. Ravetch ◽  
Jonathan C. Poe ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Effector Cell ◽  
Fc Receptor ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Antibody Immunotherapy ◽  
Cd20 Antibody ◽  
Anti Cd20 ◽  
Cd20 Antibodies

Anti-CD20 antibody immunotherapy effectively treats non-Hodgkin's lymphoma and autoimmune disease. However, the cellular and molecular pathways for B cell depletion remain undefined because human mechanistic studies are limited. Proposed mechanisms include antibody-, effector cell–, and complement-dependent cytotoxicity, the disruption of CD20 signaling pathways, and the induction of apoptosis. To identify the mechanisms for B cell depletion in vivo, a new mouse model for anti-CD20 immunotherapy was developed using a panel of twelve mouse anti–mouse CD20 monoclonal antibodies representing all four immunoglobulin G isotypes. Anti-CD20 antibodies rapidly depleted the vast majority of circulating and tissue B cells in an isotype-restricted manner that was completely dependent on effector cell Fc receptor expression. B cell depletion used both FcγRI- and FcγRIII-dependent pathways, whereas B cells were not eliminated in FcR common γ chain–deficient mice. Monocytes were the dominant effector cells for B cell depletion, with no demonstrable role for T or natural killer cells. Although most anti-CD20 antibodies activated complement in vitro, B cell depletion was completely effective in mice with genetic deficiencies in C3, C4, or C1q complement components. That the innate monocyte network depletes B cells through FcγR-dependent pathways during anti-CD20 immunotherapy has important clinical implications for anti-CD20 and other antibody-based therapies.

scholarly journals Apoptosis and macrophage-mediated deletion of precursor B cells in the bone marrow of E mu-myc transgenic mice

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2784-2794 ◽  
Author(s):  
KA Jacobsen ◽  
VS Prasad ◽  
CL Sidman ◽  
DG Osmond
Keyword(s):  
Bone Marrow ◽  
Cell Death ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
Apoptotic Cell ◽  
Cell Loss ◽  
Apoptotic Cell Death ◽  
B Lineage ◽  
Precursor B Cells

Abstract Transgenic mice expressing the c-myc proto-oncogene under the control of the Ig heavy chain enhancer (E mu-myc) all eventually develop clonal pre-B- or B-cell tumors. The preneoplastic period is characterized by increased polyclonal proliferation of pro-B and pre-B cells in the bone marrow (BM) associated with a reduced number of B cells, suggesting a high degree of B-cell loss. To examine the mechanisms of this cell loss, we have identified B220+ B-lineage cells within the BM of pretumorous E mu-myc transgenic mice by in vivo radiolabeling and electron microscope radioautography. Large mitotic B220(+)-labeled cells form prominent clusters in the extravascular compartment of the BM. Some B220+ small lymphocytes, as well as large lymphoid cells, enter BM sinusoids. However, in addition, large numbers of B220+ cells exhibit nuclear chromatin condensation, fragmentation, and other morphologic features characteristic of apoptotic cell death. Propidium iodide staining and flow cytometry of BM cells from pretumorous E mu- myc transgenic mice, as well as agarose gel electrophoresis of DNA, confirm extensive apoptosis. Many B220+ apoptotic cells are closely associated with the extensive processes of prominent macrophages that contain numerous B220+ apoptotic bodies and complex lysosomal systems. These results suggest that the constitutive expression of c-myc oncogene in BM B-lineage cells, which increases the proliferation of precursor B cells, also leads to increased apoptotic cell death and rapid elimination by resident macrophages. Further mutations may be needed to block these protective mechanisms and permit surviving c-myc- dysregulated cells to leave the BM and to initiate tumorigenesis.

scholarly journals Apoptosis and macrophage-mediated deletion of precursor B cells in the bone marrow of E mu-myc transgenic mice

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2784-2794 ◽  
Author(s):  
KA Jacobsen ◽  
VS Prasad ◽  
CL Sidman ◽  
DG Osmond
Keyword(s):  
Bone Marrow ◽  
Cell Death ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
Apoptotic Cell ◽  
Cell Loss ◽  
Apoptotic Cell Death ◽  
B Lineage ◽  
Precursor B Cells

Transgenic mice expressing the c-myc proto-oncogene under the control of the Ig heavy chain enhancer (E mu-myc) all eventually develop clonal pre-B- or B-cell tumors. The preneoplastic period is characterized by increased polyclonal proliferation of pro-B and pre-B cells in the bone marrow (BM) associated with a reduced number of B cells, suggesting a high degree of B-cell loss. To examine the mechanisms of this cell loss, we have identified B220+ B-lineage cells within the BM of pretumorous E mu-myc transgenic mice by in vivo radiolabeling and electron microscope radioautography. Large mitotic B220(+)-labeled cells form prominent clusters in the extravascular compartment of the BM. Some B220+ small lymphocytes, as well as large lymphoid cells, enter BM sinusoids. However, in addition, large numbers of B220+ cells exhibit nuclear chromatin condensation, fragmentation, and other morphologic features characteristic of apoptotic cell death. Propidium iodide staining and flow cytometry of BM cells from pretumorous E mu- myc transgenic mice, as well as agarose gel electrophoresis of DNA, confirm extensive apoptosis. Many B220+ apoptotic cells are closely associated with the extensive processes of prominent macrophages that contain numerous B220+ apoptotic bodies and complex lysosomal systems. These results suggest that the constitutive expression of c-myc oncogene in BM B-lineage cells, which increases the proliferation of precursor B cells, also leads to increased apoptotic cell death and rapid elimination by resident macrophages. Further mutations may be needed to block these protective mechanisms and permit surviving c-myc- dysregulated cells to leave the BM and to initiate tumorigenesis.

B lymphocytes inactivation by Ibrutinib limits endometriosis progression in mice

2019 ◽  
Vol 34 (7) ◽  
pp. 1225-1234 ◽  
Author(s):  
L G C Riccio ◽  
M Jeljeli ◽  
P Santulli ◽  
S Chouzenoux ◽  
L Doridot ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Peritoneal Cavity ◽  
B Cell Depletion ◽  
Regulatory B Cells ◽  
Btk Inhibitor ◽  
Cd20 Antibody ◽  
Anti Cd20 ◽  
And Control

Abstract STUDY QUESTION What are the effects of B lymphocyte inactivation or depletion on the progression of endometriosis? SUMMARY ANSWER Skewing activated B cells toward regulatory B cells (Bregs) by Bruton’s tyrosine kinase (Btk) inhibition using Ibrutinib prevents endometriosis progression in mice while B cell depletion using an anti-CD20 antibody has no effect. WHAT IS KNOWN ALREADY A polyclonal activation of B cells and the presence of anti-endometrial autoantibodies have been described in a large proportion of women with endometriosis though their exact role in the disease mechanisms remains unclear. STUDY DESIGN, SIZE, DURATION This study included comparison of endometriosis progression for 21 days in control mice versus animals treated with the anti-CD20 depleting antibody or with the Btk inhibitor Ibrutinib that prevents B cell activation. PARTICIPANTS/MATERIALS, SETTING, METHODS After syngeneic endometrial transplantation, murine endometriotic lesions were compared between treated and control mice using volume, weight, ultrasonography, histology and target genes expression in lesions. Phenotyping of activated and regulatory B cells, T lymphocytes and macrophages was performed by flow cytometry on isolated spleen and peritoneal cells. Cytokines were assayed by ELISA. MAIN RESULTS AND THE ROLE OF CHANCE Btk inhibitor Ibrutinib prevented lesion growth, reduced mRNA expression of cyclooxygenase-2, alpha smooth muscle actin and type I collagen in the lesions and skewed activated B cells toward Bregs in the spleen and peritoneal cavity of mice with endometriosis. In addition, the number of M2 macrophages decreased in the peritoneal cavity of Ibrutinib-treated mice compared to anti-CD20 and control mice. Depletion of B cells using an anti-CD20 antibody had no effect on activity and growth of endometriotic lesions and neither on the macrophages, compared to control mice. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION It is still unclear whether B cell depletion by the anti-CD20 or inactivation by Ibrutinib can prevent establishment and/or progression of endometriosis in humans. WIDER IMPLICATIONS OF THE FINDINGS Further investigation may contribute to clarifying the role of B cell subsets in human endometriosis. STUDY FUNDING/COMPETING INTEREST(S) This research was supported by a grant of Institut National de la Santé et de la Recherche Médicale and Paris Descartes University. None of the authors has any conflict of interest to disclose.

scholarly journals CNS Autoimmune Responses in BCMA-Deficient Mice Provide Insight for the Failure of Atacicept in MS

2021 ◽  
Vol 8 (3) ◽  
pp. e973
Author(s):  
Gaurav Kumar ◽  
Zahra Maria ◽  
Uday Kohli ◽  
Agnieshka Agasing ◽  
James L. Quinn ◽  
...  
Keyword(s):  
Cell Culture ◽  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Inflammatory Responses ◽  
Cell Responses ◽  
Cd20 Antibody ◽  
B Cell Responses ◽  
Anti Cd20 ◽  
Deficient Mice

ObjectiveB cells have emerged as a therapeutic target for MS. Anti-CD20 antibodies, which deplete B cells, are effective therapies for MS. However, atacicept (TACI-Fc), which blocks BAFF and APRIL and reduces B cells, unexpectedly exacerbates MS. We tested the hypothesis that B cell maturation antigen (BCMA), a receptor for BAFF and APRIL, plays a role in the paradoxical effects of anti-CD20 antibody and TACI-Fc using experimental autoimmune encephalomyelitis (EAE).MethodsEAE was induced in wild-type (BCMA+/+) and BCMA-deficient (BCMA−/−) mice with an immunization of rodent myelin oligodendrocyte glycoprotein (MOG)35–55 peptide. Treatment with anti-CD20 antibody, TACI-Fc, and isotype controls was administered by intraperitoneal injections. CNS infiltration was evaluated by histology; immune cell phenotypes were evaluated by flow cytometry; MOG-specific antibodies were determined by ELISA. Mixed bone marrow chimeras and cell culture assays were used to identify the specific subsets of immune cells affected by BCMA deficiency.ResultsFirst, we found that BCMA−/− mice had more severe EAE compared with BCMA+/+ mice and the increased disease was associated with elevated anti-MOG B-cell responses. Second, we found that anti-CD20 therapy attenuated EAE in BCMA−/− mice but not in BCMA+/+ mice. Third, TACI-Fc attenuated EAE in BCMA+/+ mice but not in BCMA−/− mice. Mixed bone marrow chimeric and cell culture experiments demonstrated that BCMA deficiency elevates inflammatory B-cell responses but inhibits inflammatory responses in macrophages.ConclusionsBCMA has multifaceted roles during inflammation that affects therapeutic efficacies of anti-CD20 and TACI-Fc in EAE. Our results from BCMA-deficient mice provide insights into the failure of atacicept in MS.

scholarly journals B cells reappear less mature and more activated after their anti-CD20–mediated depletion in multiple sclerosis

2020 ◽  
Vol 117 (41) ◽  
pp. 25690-25699
Author(s):  
Nitzan Nissimov ◽  
Zivar Hajiyeva ◽  
Sebastian Torke ◽  
Katja Grondey ◽  
Wolfgang Brück ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
B Cell Depletion ◽  
Time Intervals ◽  
Activation Markers ◽  
Cell Pool ◽  
Relapsing Remitting ◽  
Enhanced Expression ◽  
Anti Cd20

B cell depletion via anti-CD20 antibodies is a highly effective treatment for multiple sclerosis (MS). However, little is known about the maturation/activation stage of the returning B cell population after treatment cessation and the wider effects on other immune cells. In the present study, 15 relapsing-remitting MS patients receiving 1,000 mg of rituximab were included. B, T, and myeloid cells were analyzed before anti-CD20 administration and in different time intervals thereafter over a period of 24 mo. In comparison to the phenotype before anti-CD20 treatment, the reappearing B cell pool revealed a less mature and more activated phenotype: 1) reappearing B cells were significantly enriched in transitional (before: 10.1 ± 1.9%, after: 58.8 ± 5.2%) and mature naive phenotypes (before: 45.5 ± 3.1%, after: 25.1 ± 3.5%); 2) the frequency of memory B cells was reduced (before: 36.7 ± 3.1%, after: 8.9 ± 1.7%); and 3) reappearing B cells showed an enhanced expression of activation markers CD25 (before: 2.1 ± 0.4%, after: 9.3 ± 2.1%) and CD69 (before: 5.9 ± 1.0%, after: 21.4 ± 3.0%), and expressed significantly higher levels of costimulatory CD40 and CD86. T cells showed 1) a persistent increase in naive (CD4+: before: 11.8 ± 1.3%, after: 18.4 ± 3.4%; CD8+: before: 12.5 ± 1.4%, after: 16.5 ± 2.3%) and 2) a decrease in terminally differentiated subsets (CD4+: before: 47.3 ± 3.2%, after: 34.4 ± 3.7%; CD8+: before: 53.7 ± 2.1%, after: 49.1 ± 2.7%).

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